The osteomeatal complex (OMC) is a key area in the pathogenesis of sinusitis. The OMC includes the middle meatus and the narrow channels that provide the pathway for mucociliary clearance and ventilation of the anterior ethmoid, maxillary, and frontal sinuses. Thus, relatively minor swelling in this area, such as that associated with upper respiratory tract infections or allergic rhinitis, may lead to obstruction of any one or combination of these sinus cavities. As a result of blockage in the OMC, sinusitis may develop due to the accumulation of mucus, inflammatory cells, and bacteria, presence of low oxygen tension, and impaired immune responses in the OMC and surrounding tissues.
Medical treatment regimens used for sinusitis may be used to treat OMC inflammation. Typical medical treatment regimes may include a combination of oral antibiotics, topical or oral decongestants, topical steroid nasal sprays or solutions, or injectable oral steroids such as prednisone. Systemic methods (e.g., oral and injectables) commonly have significant disadvantages relating to side effects from the exposure of the entire body to the effects of the active agent. Topical methods (e.g., nasal sprays and other solutions) commonly have disadvantages relating to the limited site availability of the active agents both nasally and at the inflamed OMC anatomy (typically less than a 30 percent nasal drug delivered dose efficiency, and presumably far less at the specific OMC anatomy) as well as a short drug residence time at the inflamed site due to the effect of mucociliary clearance (typically less than 30 minutes dose residence time within the nasal passage).
When medical therapy fails, surgical treatment such as functional endoscopic sinus surgery (FESS) may be an alternative. The goal of FESS, and of sinus surgery generally, is to improve the drainage of the sinuses by enlarging the ostia of the maxillary and frontal sinuses, and opening the ethmoid sinus area by removing the ethmoid air cells under direct visualization. However, surgery itself creates inflammation, which can lead to post-operative fibrosis, stenosis, and/or polyposis that frequently obstructs the newly opened sinuses, requiring the surgeon to reoperate to revise the ostia and insert stenting devices to keep sinus ostia patent. Even in the resected post-surgical anatomy, access to many of the inflamed regions of the OMC remains difficult.
Other methods of post-surgical adjunctive drug delivery have required endoscopic placement of various drug hydrated packing materials, typically resident for a week or less at a time, and presumably delivering drug for shorter periods than the packing material residence time as only an acute one-time instillation of active agents is possible (as described in Shikani, A H, Use of Antibiotics for Expansion of the Merocel Packing Following Endoscopic Sinus Surgery, ENT Journal 75 (8): 524-527 (1996)). Such approaches are unlikely to allow consistent or controllable sustained release of active agents. Still other described approaches involve acute endoscopic injection of active agent releasing depots, as in the intramuscular injection of steroids (e.g., triamcinolone acetonide suspensions such as Kenalog) into adjacent soft tissue. These approaches require invasive rather than topical methods (e.g., intramuscular injection at a site), and neither treat the OMC region directly (which is primarily thin tissue membranes over bony cavities not suitable for an intramuscular depot) nor treat without significant collateral systemic and adjacent tissue exposure and adverse effects (e.g., the use of Kenalog in the paranasal and sinus anatomy has been linked to both systemic adrenal suppression as well as cases of ipsilateral blindness, in many cases permanent).
Consequently, new devices, methods, and kits to locally administer and provide sustained release of active agents directed to the OMC for treating sinusitis and its related respiratory conditions are desirable.